1. Field of the Invention
This invention relates to an instrument panel structure of an automotive vehicle body. More particularly, the invention relates to an instrument panel structure having a mechanism for preventing deformation of a support member of the instrument panel structure during a collision and which adequately supports elements such as a steering apparatus or a knee protector during a collision.
2. Description of Related Art
Typically, instrument panel structures of a front body of an automotive vehicle include a support member, extending in a transverse direction of the front body, for supporting a steering apparatus, a knee protector for relieving a shock applied to a driver's knees upon a collision, etc. Such an instrument panel structure is known from, for instance, Japanese Unexamined Utility Model Publication No. 2-92,359.
For the purpose of providing a better understanding of such an instrument panel structure, reference is made to FIG. 4. As shown, an instrument panel structure has a support member 1, in a form of an elongated pipe, which extends in a transverse direction of a front body and supports a steering apparatus 3 and a knee protector 5. If the driver M is thrown forward upon the occurrence of a collision of the automotive vehicle, the knee protector 5 will be hit by the driver's knees N, as shown by a chained line. Simultaneously, a steering wheel 8 of the steering apparatus 3 will be loaded by the upper body of the driver. As a result, the support member 1 is subjected to a thrust-up force exerted on the knee protector 5 by the knees N and a "swing force" or torque applied by the steering apparatus 3, and specifically a steering column 6 thereof, when the steering apparatus 3 swings or turns forward around its supported distal end due to the impact load applied to the steering wheel 8 by the driver's upper body. The support member 1, therefore, may possibly be deformed upward in a direction indicated by an arrow P. Such forward movement of the steering apparatus 3 is enhanced if an air bag is assembled in the steering apparatus 3. Deformation of the support member of the instrument panel structure described in the Japanese publication may cause a decline in structural resistance of the automotive vehicle body against collisions.
In order to absorb or suppress shock energy acting on a steering wheel during a collision, it is typical to instal a collapsible steering column having a dual-pipe structure in the steering apparatus. However, if upward deformation of the support member displaces the steering wheel forward and the driver's upper body hits the steering wheel in a direction which is different from an axial direction of the steering column or a direction in which the steering column is intended to collapse, the steering column will not properly collapse and absorb shock energy applied to the steering wheel.